Question

Analyse the concept map given below and if I make a mistake, reconstruct it.

Answer 1

Hint: These are a part of the pharynx which is about 12 cm long vertical canal beyond the soft palate. The food and the air passages cross here. The pharynx may be divided into three parts- nasopharynx, oropharynx and laryngopharynx.

Complete answer:
> Nasopharynx- It is the upper part of the pharynx and has internal nares in the roof and oval opening of the Eustachian tubes on the sides leading to the middle ears. A mass of lymphoid tissue lies in the back wall of the nasopharynx. It is called pharyngeal tonsil or adenoid.

> Oropharynx- It is the middle part of the pharynx. The oral cavity opens into it. An ovoid mass of lymphoid tissue called palatine tonsil lies on the either side of the pharynx between two vertical folds. These are often removed.

> Laryngopharynx- It is the lower part of the pharynx that leads into the food pipe or the esophagus behind and into the voice box or larynx in front and the opening to the larynx is called the glottis. It bears a leaf-like cartilaginous flap called the epiglottis at its front border. The epiglottis projects into the oropharynx opposite the uvula. During the swallowing, it covers the glottis to prevent the entry of food into it.

The more apt concept map for this should be:

Note: The function of the pharynx as a part of the digestive tract is merely to serve as a passageway for the food from the oral cavity to the oesophagus. It has in its walls the voluntary muscles that help in swallowing movements.